Search Publications
Investigating the magnetospheric accretion process in the young pre-transitional disk system DoAr 44 (V2062 Oph). A multiwavelength interferometric, spectropolarimetric, and photometric observing campaign
Moutou, C.; Bayo, A.; Donati, J. -F. +13 more
Context. Young stars interact with their accretion disk through their strong magnetosphere.
Aims: We aim to investigate the magnetospheric accretion/ejection process in the young stellar system DoAr 44 (V2062 Oph).
Methods: We monitored the system over several rotational cycles, combining high-resolution spectropolarimetry at both optica…
The spatial evolution of young massive clusters. II. Looking for imprints of star formation in NGC 2264 with Gaia DR2
Hacar, Álvaro; Buckner, Anne S. M.; Khorrami, Zeinab +12 more
Context. Better understanding of star formation in clusters with high-mass stars requires rigorous dynamical and spatial analyses of star-forming regions.
Aims: We seek to demonstrate that "INDICATE" is a powerful spatial analysis tool which when combined with kinematic data from Gaia DR2 can be used to probe star formation history in a robus…
A dusty benchmark brown dwarf near the ice line of HD 72946
Absil, O.; Henning, T.; Brandner, W. +12 more
Context. HD 72946 is a bright and nearby solar-type star hosting a low-mass companion at long period (P ∼ 16 yr) detected with the radial velocity (RV) method. The companion has a minimum mass of 60.4 ± 2.2 MJ and might be a brown dwarf. Its expected semi-major axis of ∼243 mas makes it a suitable target for further characterization wit…
Spatially resolved spectroscopy of close massive visual binaries with HST/STIS. I. Seven O-type systems
Maíz Apellániz, J.; Barbá, R. H.
Context. The spectroscopic characterization of many O-type stars is hampered by a nearby companion.
Aims: We want to obtain spatially resolved spectroscopy of close O-type visual binaries to derive their spectral types.
Methods: We used the Space Telescope Imaging Spectrograph (STIS) of the Hubble Space Telescope (HST) to obtain long-sli…
Chandra reveals a luminous Compton-thick QSO powering a Lyα blob in a z = 4 starbursting protocluster
Ivison, R. J.; Lehmer, B. D.; Bauer, F. E. +7 more
Context. Galaxy clusters in the local universe descend from high-redshift overdense regions known as protoclusters. The large gas reservoirs and high rate of galaxy interaction in protoclusters are expected to enhance star-formation activity and trigger luminous supermassive black-hole accretion in the nuclear regions of the host galaxies.
Ai…
The role of small-scale surface motions in the transfer of twist to a solar jet from a remote stable flux rope
Aulanier, Guillaume; Schmieder, Brigitte; Joshi, Reetika +2 more
Context. Jets often have a helical structure containing ejected plasma that is both hot and also cooler and denser than the corona. Various mechanisms have been proposed to explain how jets are triggered, primarily attributed to a magnetic reconnection between the emergence of magnetic flux and environment or that of twisted photospheric motions t…
Progenitor properties of type II supernovae: fitting to hydrodynamical models using Markov chain Monte Carlo methods
González-Gaitán, S.; Folatelli, G.; Anderson, J. P. +3 more
Context. The progenitor and explosion properties of type II supernovae (SNe II) are fundamental to understanding the evolution of massive stars. Particular attention has been paid to the initial masses of their progenitors, but despite the efforts made, the range of initial masses is still uncertain. Direct imaging of progenitors in pre-explosion …
Expectations on mass determination using astrometric microlensing by Gaia
Bastian, U.; Wambsganss, J.; Klüter, J.
Context. Astrometric gravitational microlensing can be used to determine the mass of a single star (the lens) with an accuracy of a few percent. To do so, precise measurements of the angular separations between lens and background star with an accuracy below 1 milli - arcsec at different epochs are needed. Therefore only the most accurate instrume…
An ALMA/NOEMA study of gas dissipation and dust evolution in the 5 Myr-old HD 141569A hybrid disc
Augereau, J. -C.; Boccaletti, A.; Chapillon, E. +5 more
Context. The study of gas-rich debris discs is fundamental to characterising the transition between protoplanetary discs and debris discs.
Aims: We determine the physical parameters of the brightest gas-rich debris disc orbiting HD 141569A.
Methods: We analyse images from the NOrthern Extended Millimeter Array (NOEMA)1 and the…
A charging model for the Rosetta spacecraft
Henri, P.; Eriksson, A. I.; Johansson, F. L. +5 more
Context. The electrostatic potential of a spacecraft, VS, is important for the capabilities of in situ plasma measurements. Rosetta has been found to be negatively charged during most of the comet mission and even more so in denser plasmas.
Aims: Our goal is to investigate how the negative VS correlates with electron den…